# -*- coding: latin-1 -*-
# Copyright (c) 2007-2009 Jorge Ortiz Romo <jortizromo@gmail.com>
#                         Freymam Vallejo Cuero <freturn@gmail.com>
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:

# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.


'''
Created on Dec 7, 2009

@author: Freymam Vallejo
@author: Jorge Ortiz
'''

from iasna_core.sna.graph import Diameter
import Connectivity

def digraph_diameter(digraph):
    """
    Find the diameter for a digraph.

    @type graph: graph, digraph.
    @param graph: graph, DiGraph.

    @rtype: number.
    @return: the diameter. Return 'undifined' if the digraph is not connected.
    """

    if Connectivity.digraph_connectivity(digraph)== 'Ordinary connected'or Connectivity.digraph_connectivity(digraph)== 'Unilaterally connected':
        return 'undefined'
    else:
        return Diameter.diameter(digraph)
    
                
        


                
